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condor_gpu_discovery - Man Page


condor_gpu_discovery — HTCondor Manual

Output GPU-related ClassAd attributes


condor_gpu_discovery -help

condor_gpu_discovery [<options> ]


condor_gpu_discovery outputs ClassAd attributes corresponding to a host's GPU capabilities. It can presently report CUDA and OpenCL devices; which type(s) of device(s) it reports is determined by which libraries, if any, it can find when it runs; this reflects what GPU jobs will find on that host when they run. (Note that some HTCondor configuration settings may cause the environment to differ between jobs and the HTCondor daemons in ways that change library discovery.)

If CUDA_VISIBLE_DEVICES or GPU_DEVICE_ORDINAL is set in the environment when condor_gpu_discovery is run, it will report only devices present in the those lists.

This tool is not available for MAC OS platforms.

With no command line options, the single ClassAd attribute DetectedGPUs is printed. If the value is 0, no GPUs were detected. If one or more GPUS were detected, the value is a string, presented as a comma and space separated list of the GPUs discovered, where each is given a name further used as the prefix string in other attribute names. Where there is more than one GPU of a particular type, the prefix string includes an GPU id value identifying the device; these can be integer values that monotonically increase from 0 when the -by-index option is used or globally unique identifiers when the -short-uuid or -uuid argument is used.

For example, a discovery of two GPUs with -by-index may output

DetectedGPUs="CUDA0, CUDA1"

Further command line options use "CUDA" either with or without one of the integer values 0 or 1 as the name of the device properties ad for -nested properties, or as the prefix string in attribute names when -not-nested properties are chosen.

For machines with more than one or two NVIDIA devices, it is recommended that you also use the -short-uuid or -uuid option.  The uuid value assigned by NVIDA to each GPU is unique, so  using this option provides stable device identifiers for your devices. The -short-uuid option uses only part of the uuid, but it is highly likely to still be unique for devices on a single machine. As of HTCondor 9.0 -short-uuid is the default. When -short-uuid is used, discovery of two GPUs may look like this

DetectedGPUs="GPU-ddc1c098, GPU-9dc7c6d6"

Any NVIDIA runtime library later than 9.0 will accept the above identifiers in the CUDA_VISIBLE_DEVICES environment variable.

If the NVML libary is available, and a multi-instance GPU (MIG) -capable device is present, has MIG enabled, and has created compute instances for each MIG instance, condor_gpu_discovery will report those instance as distinct devices.  Their names will be in the long UUID form unless the -short-uuid option is used, because they can not be enumerated via CUDA.  MIG instances don't have some of the properties reported by the -properties, -extra, and -dynamic options; these properties will be omitted.  If MIG is enabled on any GPU in the system, some properties become unavailable for every GPU in the system; condor_gpu_discovery will report what it can.



Print usage information and exit.


In addition to the DetectedGPUs attribute, display some of the attributes of the GPUs. Each of these attributes will be in a nested ClassAd (-nested) or have a prefix string at the beginning of its name (-not-nested). The displayed CUDA attributes are Capability, DeviceName, DriverVersion, ECCEnabled, GlobalMemoryMb, and RuntimeVersion. The displayed Open CL attributes are DeviceName, ECCEnabled, OpenCLVersion, and GlobalMemoryMb.

Default. Display properties that are common to all GPUs in a Common nested ClassAd,

and properties that are not common to all in a nested ClassAd using the GPUid as the ClassAd name.  Use the -not-nested argument to disable nested ClassAds and return to the older behavior of using a prefix string for individual property attributes.

Display properties that are common to all GPUs using a CUDA or OCL as

the attribute prefix, and properties that are not common to all using a GPUid prefix.  Versions of condor_gpu_discovery prior to 9.11.0 support only this mode.


Display more attributes of the GPUs. Each of these attributes will be added to a nested property ClassAd (-nested) or have a prefix string at the beginning of its name (-not-nested). The additional CUDA attributes are ClockMhz, ComputeUnits, and CoresPerCU. The additional Open CL attributes are ClockMhz and ComputeUnits.


Display attributes of NVIDIA devices that change values as the GPU is working. Each of these attributes will be added to the the nested property ClassAd (-nested) or have a prefix string at the beginning of its name (-not-nested). These are FanSpeedPct, BoardTempC, DieTempC, EccErrorsSingleBit, and EccErrorsDoubleBit.


When displaying attribute values, assume that the machine has a heterogeneous set of GPUs, so always include the integer value in the prefix string.

-device <N>

Display properties only for GPU device <N>, where <N> is the integer value defined for the prefix string. This option may be specified more than once; additional <N> are listed along with the first. This option adds to the devices(s) specified by the environment variables CUDA_VISIBLE_DEVICES and GPU_DEVICE_ORDINAL, if any.

-tag string

Set the resource tag portion of the intended machine ClassAd attribute Detected<ResourceTag> to be string. If this option is not specified, the resource tag is "GPUs", resulting in attribute name DetectedGPUs.

-prefix str

When naming -not-nested attributes, use str as the prefix string. When this option is not specified, the prefix string is either CUDA or OCL unless -uuid or -short-uuid is also used.


Use the prefix and device index as the device identifier.


Use the first 8 characters of the NVIDIA uuid as the device identifier. When this option is used, devices will be shown as GPU-<xxxxxxxx> where <xxxxxxxx> is the first 8 hex digits of the NVIDIA device uuid.  Unlike device indices, the uuid of a device will not change of other devices are taken offline or drained.


Use the full NVIDIA uuid as the device identifier rather than the device index.


For testing purposes, assume that N devices of type D were detected, And N2 devices of type D2, etc. No discovery software is invoked. D can be a value from 0 to 6 which selects a simulated a GPU from the following table.

Simulated Gpus

0GeForce GT 3301.21024
1GeForce GTX 4802.01536
2Tesla V100-PCIE-16GB7.024220
3TITAN RTX7.524220
5NVIDIA A100-SXM4-40GB MIG 3g.20gb8.020096
6NVIDIA A100-SXM4-40GB MIG 1g.5gb8.04864

Prefer detection via OpenCL rather than CUDA. Without this option, CUDA detection software is invoked first, and no further Open CL software is invoked if CUDA devices are detected.


Do only CUDA detection.


For Windows platforms only, use a CUDA driver rather than the CUDA run time.


Output in the syntax of HTCondor configuration, instead of ClassAd language. An additional attribute is produced NUM_DETECTED_GPUs which is set to the number of GPUs detected.

-repeat [N]

Repeat listed GPUs N (default 2) times.  This results in a list that looks like CUDA0, CUDA1, CUDA0, CUDA1.

If used with -divide, the last one on the command-line wins, but you must specify 2 if you want it; the default value only applies to the first flag.

-divide [N]

Like -repeat, except also divide the attribute GlobalMemoryMb by N.  This may help you avoid overcommitting your GPU's memory.

If used with -repeat, the last one on the command-line wins, but you must specify 2 if you want it; the default value only applies to the first flag.


When repeating GPUs, repeat each GPU N times, not the whole list. This results in a list that looks like CUDA0, CUDA0, CUDA1, CUDA1.


This option suppresses the DetectedGpus attribute so that the output is suitable for use with condor_startd cron. Combine this option with the -dynamic option to periodically refresh the dynamic Gpu information such as temperature. For example, to refresh GPU temperatures every 5 minutes

use FEATURE : StartdCronPeriodic(DYNGPUS, 5*60, $(LIBEXEC)/condor_gpu_discovery, -dynamic -cron)

For interactive use of the tool, output extra information to show detection while in progress.


Show diagnostic information, to aid in tool development.

Exit Status

condor_gpu_discovery will exit with a status value of 0 (zero) upon success, and it will exit with the value 1 (one) upon failure.


HTCondor Team


Jan 24, 2024 HTCondor Manual